We've got 2 at South Yorkshire Energy Centre (www.syec.co.uk). I declare an interest in that a local dealer gave us one of them, but as soon as I first saw one (at Hebden Bridge Alternative Technology Centre (www.alternativetechnology.org.uk)) I was won over. I simply did not believe the claims at first - light going round corners, pah! - but I am now an evangelical convert.

Ours is a Solatube.

Have fun with yours.

Nick

Tony,
I base my liking for them on the assumption that you are 'ducting light in' so a space which cannot be served by a window or a roof light. Our upper one serves an internal WC. It kinks up through the attic roof space and out the rear roof. It would have been well nigh impossible to 'borrow' any light from a roof-light. Of course I agree, if you can fit a window, fit a window, but where you can't, they're good.

I guess the question is how long does it take to recover the outlay of the sunpipe by way of reduced electricity for lighting?

They also do not have a very good u value so I would be wary of heat loss through them.
Sunpipe quote values between 1.6 and 2 as compared to 0.2 for a good roof.

Also they are a potential source of air leakage as they will penetrate the air leakage membrane.

Thanks all,

Yes its to duct light down through an upper story (approx 2.5m drop) to illuminate a dark room area and of course natural light is best. If its just a case of the money i'd have left the light on.
So far only SolaTube gets anyones vote. Any others??

Cheers

Mike (up north)

Hi Nick, I agree it is not as simplistic as I suggested and it is not just about electric bills. Though if you have for example a 15W CFL instead then it will take you quite a while to run up a bill of around £180 plus instalation costs

Personally. I would use one if the daylighting issue was that immportant. I hear velux make a good one

I used a light tube in our straw bale house and the mistake was that the longer you extend it, the less light. We extended it about 2.5metres and so the light from it is a bit pathetic. They are very expensive and don't need to be. I bought mine from the loft shop.

Of course another obvious point is how much is the room used when there's sunlight anyway. For many domestic buildings not a lot probably. I can't help thinking that I could live without natural light in the WC!
Good for offices perhaps though.

Proper window in the roof and you won't have turn the light on to read and you will get controllable ventilation too.

Thanks all,
A proper window would be nice except that it would only illuminate the room below not the room on the floor below ie the ground floor, I'd need to put a window in the floor as well. Looks like 3m is going to be much too long for a tube. It would have run vertically down from a flat roof (even worse I think) in an enclosed cupboard to the room below. I’d hoped 350mm diameter would do it.

Any other suggestions?

Cheers

Fitted these several years ago in new build as a bit of a gimmick but they went down a storm.
Recently been thinking about using them for light at night! Was thinking along the lines of a halo of solar garden lights around one that would provide light until midnightish, do you reckon it would work?
The best ideas always come after a glass or two of vino! That of a load of gibberish.

I was very interested to see comments on sun tubes. I have a 1870s railway carriage ( a "passenger brake") which I paint in. But all the light comes in from side windows, the main pool of light being about knee lheight. After such a dull grey summer I long for natural overhead light and sun tubes were suggested. I tried to find these on the net but they were all US firms and/or very very expensive. The roof is formed of 34 ft long teak(?) planks, with 10" circular cutouts where a man would drop down an oil lamp into each compartment! I had thought of taking out two complete planks at the apex of the curve of the carriage roof and replacing them with polycarbonate 5 wall sheet. The lack of shadows from the diffuser under a suntube attracts me, but not if cuts down the amount of light. I have to refelt the roof anyway, so was taking the opportunity to get natural light at the same time.

Any helpful comments?

Clerestory.

IMHO Natural light is worth paying for, houses are not necessarily just 'machines for living',

....but..... (that was a big 'but' by the way, not to be confused with a 'big butt', which is entirely different)... does the light from Sun-tubes actually feel like natural light...?

J

Compared to a glass panel in the roof --- no.

Hi Mike (up north),
There are several manufacturers of sun pipe systems: Monodraught is probably the key player in this country, then you have Sola Skylights, Sola Tube, and Velux. Monodraught and Sola Tube produce rigid systems, Sola Skylights produce Rigid and Flexible systems, Velux used to produce just Flexible but have just bought out Monodraught so there is likely to be a merging of products in the not too distant future.

The first point to make is that these things do work. The key to a bright room is making sure you get the right size unit. Install one that's too small and all you have is a glowing circle of light.

There are differences in the systems, no two ways about it. The rigid systems do carry more light due to the level of reflectivity achieved inside the tube. However, they do cost more. A fair comment might be that more light = more expensive, true. But you'll really only see such a benefit in quite a large room. A standard room, let's say 15ft x 15ft, would benefit from a 500mm rigid system or a 550mm Flexible system with a 3mtr. distance from roof to ceiling. The difference in cost is worth looking at: the Rigid system (based on Monodraught's web site) is going to cost around £700.00 as the standard kit requires the purchase of additional sections of pipe to cover 3 metres. The Flexible system (based on Sola Skylight's web site) is £345.00 and comes with 3 metres of flexible tube as standard. Not only that, the Flexible system is much easier to fit. A good installer will do it in less than 2 hours, a DIYer could do it in 4. The rigid system is a lot more fiddly, requiring rivets, more measuring etc. Not really a DIY job.

Now, if you go to http://www.solaskylights.com/light_calculation.html, you can see the results of a study carried out by Durham University on the light emission from both Rigid and Flexible systems. A point to bear in mind is that once you compare the out put from either system to a 100watt bulb, you get the idea of how much light gets into the room. By the time you get to 1000+ lux the human eye is struggling to tell the difference between that and 1500 Lux - it's just uncomfortable.

Next you may want to consider ventillation. Most buildings require passive ventilation to keep them in good condition. Only the Sola Skylights system comes with passive ventilation as standard (although you can choose not to use it if you prefer) the others require a different unit. And you may want to consider a double-glazed diffuser for when it gets to winter because heat can travel up these things. The u value is about the same as a window in most of them.

Another thing, obviously, is what to do at night. Most of them allow the fitting of a light inside the tube just above the diffuser so that you can light the room artificially (energy efficient bulb recommended) but you need a fairly high wattage bulb as the diffuser does impare it a bit.

The last point is overall whole life cost. These units tend to come with a fairly decent guarantee from 10 to 20 years depending on the system and they're pretty much maintenance free as the rain keeps the roof dome clean, so after the initial investment they have a zero running cost. If you start comparing the cost of running a bulb against the cost of installing a sun pipe, the sun pipe will lose. One bulb will run for a long time for £300.00 (even longer for £700.00). The benefits are that you get daylight in a room that doesn't normally have it and you aren't using any carbon once it's installed (unless you fit a light and even then you're cutting down). And, let's face it, natural light is far nicer than artificial.

Hope this helps.